1. Field of the Invention
The present invention relates to an audio processing apparatus.
2. Description of the Related Art
An audio playback system including a BD player, an AV amplifier, and a display apparatus has been used. Audio data transmitted from the BD player to the AV amplifier is obtained by encoding multichannel audio data. For example, the multichannel audio data includes, as shown in FIG. 3, a left audio signal L, a right audio signal R, a center audio signal C, a low-frequency audio signal SW, a surround left audio signal SL, a surround right audio signal SR, a surround back left audio signal SBL, and a surround back right audio signal SBR. Recently, HD (High Definition) related audio formats such as Dolby True HD, Dolby Digital Plus, and DTS-HD have appeared. In these formats, an upper left audio signal LH, an upper right audio signal RH, an outer left audio signal LW, and an outer right audio signal RW are further added.
However, when amplifiers associated with audio signals of all these channels are provided to the AV amplifier, amplifiers for 11.1 channels in total are to be provided, resulting in very high cost. Furthermore, the amplifiers for further 2 channels are needed when the left audio signal and the right audio signal are reproduced using the Bi-Amp function, resulting in very high cost. If performing the Bi-Amp function using amplifiers for the surround back left audio signal and the surround back right audio signal, the left audio signal and the right audio signal are not able to be reproduced by using the Bi-Amp function in the state that the surround back left audio signal and the surround back right audio signal are reproduced.